Field of the Invention
The present invention relates to a lock mechanism for a hand tool, in particular to pliers or crimp tools having two handles.
Description of Related Art
Pliers and crimp tools are frequently used for machining articles. A crimp tool can bend, shear, strip and crimp insulated wiring and connectors thereof. These connectors include the RJ-45 connector, a connector standardized as the 8P8C modular connector, and the RJ-11 connector, a connector for telephone connections etc. A crimp tool usually includes two handles to be grasped by a user during operation. Generally speaking, when the crimp tool is in a contracted position, the two handles abut against or are adjacent to each other, and when the crimp tool is in an expanded position, the two handles are separate from each other. As a labor saving device, some crimp tools include a biasing mechanism such as a spring for biasing one handle against the other so that the handles tend to be urged into an expanded position. Users thus only need to move the handles from the expanded position to the contracted position when using the crimp tool, while the biasing mechanism will return the handles back to the expanded position.
A crimp tool or a plier occupies smallest space when the handles are contracted and close to each other. Therefore, when the crimp tool or the plier is not in use and is to be stored, the handles thereof should first be contracted and fixed. To prevent the handles from leaving the contracted position, a plier as described in Taiwan Pat. No. I363676 is provided with a snap ring at the end of one handle to be engaged with a knob at the end of the other handle so that the two handles can be fixed after they are contracted for storage. However, the snap ring and the knob are disposed externally to the plier, and not only occupy additional space but may also cause injury.
Given the above, there is need for a lock mechanism for hand tools such as pliers or crimp tools having two handles that does not occupy additional space and is safe for users.